Data storage systems are arrangements of hardware and software that include one or more storage processors coupled to arrays of non-volatile storage devices, such as magnetic disk drives, electronic flash drives, and/or optical drives, for example. The storage processors service storage requests, arriving from host machines (“hosts”), which specify files or other data elements to be written, read, created, or deleted, for example. Software running on the storage processors manages incoming storage requests and performs various data processing tasks to organize and secure the data elements stored on the non-volatile storage devices.
Some data storage systems employ software compression and decompression to improve storage efficiency. For example, software compression involves loading compression instructions into memory and executing the instructions on stored data using one or more processing cores. A result of such software compression is that compressed data requires less storage space than the original, uncompressed data. Conversely, software decompression involves loading decompression instructions into the memory and executing the instructions on the compressed data using one or more of the processing cores, to restore the compressed data to its original, uncompressed form.
Other data storage systems perform compression and decompression in hardware. For example, a data storage system may include specialized hardware for compressing and decompressing data. The specialized hardware may be provided on the storage processor itself, e.g., as a chip, chipset, or sub-assembly, or on a separate circuit board assembly. Unlike software compression, which operates by running executable software instructions on a computer, hardware compression employs one or more ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), RISC (Reduced Instruction Set Computing) processors, and/or other specialized devices in which operations may be hard-coded and performed at high speed.